/*
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Rhino code, released
 * May 6, 1999.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1997-1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Bob Jervis
 *   Google Inc.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License Version 2 or later (the "GPL"), in which
 * case the provisions of the GPL are applicable instead of those above. If
 * you wish to allow use of your version of this file only under the terms of
 * the GPL and not to allow others to use your version of this file under the
 * MPL, indicate your decision by deleting the provisions above and replacing
 * them with the notice and other provisions required by the GPL. If you do
 * not delete the provisions above, a recipient may use your version of this
 * file under either the MPL or the GPL.
 *
 * ***** END LICENSE BLOCK ***** */

package com.google.javascript.rhino;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;

import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * <p>JSDoc information describing JavaScript code. JSDoc is represented as a
 * unified object with fields for each JSDoc annotation, even though some
 * combinations are incorrect. For instance, if a JSDoc describes an enum,
 * it cannot have information about a return type. This implementation
 * takes advantage of such incompatibilities to reuse fields for multiple
 * purposes, reducing memory consumption.</p>
 *
 * <p>Constructing {@link JSDocInfo} objects is simplified by
 * {@link JSDocInfoBuilder} which provides early incompatibility detection.</p>
 *
 */
public class JSDocInfo implements Serializable {
  private static final long serialVersionUID = 1L;

  /**
   * Visibility categories. The {@link Visibility#ordinal()} can be used as a
   * numerical indicator of privacy, where 0 is the most private. This means
   * that the {@link Visibility#compareTo} method can be used to
   * determine if a visibility is more permissive than another.
   */
  public enum Visibility {
    PRIVATE,
    PROTECTED,
    PUBLIC,

    // If visibility is not specified, we just assume that visibility
    // is inherited from the super class.
    INHERITED
  }

  private static final class LazilyInitializedInfo implements Serializable {
    private static final long serialVersionUID = 1L;

    // Function information
    JSTypeExpression baseType = null;
    List<JSTypeExpression> implementedInterfaces = null;
    Map<String, JSTypeExpression> parameters = null;
    List<JSTypeExpression> thrownTypes = null;
    String templateTypeName = null;

    // Other information
    String description = null;
    String meaning = null;
    String deprecated = null;
    String license = null;
    Set<String> suppressions = null;
    Set<String> modifies = null;
    String lendsName = null;
  }

  private static final class LazilyInitializedDocumentation {
    String sourceComment = null;
    List<Marker> markers = null;

    Map<String, String> parameters = null;
    Map<JSTypeExpression, String> throwsDescriptions = null;
    String blockDescription = null;
    String fileOverview = null;
    String returnDescription = null;
    String version = null;

    List<String> authors = null;
    List<String> sees = null;
  }

  /**
   * A piece of information in a marker containing a position with a string.
   */
  public static class StringPosition extends SourcePosition<String> {
  }

  /**
   * A piece of information in a marker containing a position with a type.
   */
  public static class TypePosition extends SourcePosition<Node> {
    public boolean hasBrackets = false;
  }

  /**
   * Defines a class for containing the parsing information
   * for this JSDocInfo. For each annotation found in the
   * JsDoc, a marker will be created indicating the annotation
   * itself, the name of the annotation (if any; for example,
   * a @param has a name, but a @return does not), the
   * textual description found on that annotation and, if applicable,
   * the type declaration. All this information is only collected
   * if documentation collection is turned on.
   */
  public static final class Marker {
    public StringPosition annotation = null;
    public StringPosition name = null;
    public StringPosition description = null;
    public TypePosition type = null;
  }

  private LazilyInitializedInfo info = null;

  private LazilyInitializedDocumentation documentation = null;

  /** The source file containing the JSDoc. */
  private String sourceName = null;

  private Visibility visibility = null;

  /**
   * The {@link #isConstant()}, {@link #isConstructor()}, {@link #isInterface},
   * {@link #isHidden()} and {@link #shouldPreserveTry()} flags as well as
   * whether the {@link #type} field stores a value for {@link #getType()},
   * {@link #getReturnType()} or {@link #getEnumParameterType()}.
   *
   * @see #setFlag(boolean, int)
   * @see #getFlag(int)
   * @see #setType(JSTypeExpression, int)
   * @see #getType(int)
   */
  private int bitset = 0x00;

  /**
   * The type for {@link #getType()}, {@link #getReturnType()} or
   * {@link #getEnumParameterType()}. The knowledge of which one is recorded is
   * stored in the {@link #bitset} field.
   *
   * @see #setType(JSTypeExpression, int)
   * @see #getType(int)
   */
  private JSTypeExpression type = null;

  /**
   * The type for {@link #getThisType()}.
   */
  private JSTypeExpression thisType = null;

  /**
   * Whether to include documentation.
   *
   * @see JSDocInfo.LazilyInitializedDocumentation
   */
  private boolean includeDocumentation = false;

  // We use a bit map to represent whether or not the JSDoc contains
  // one of the "boolean" annotation types (annotations like @constructor,
  // for which the presence of the annotation alone is significant).

  // Mask all the boolean annotation types
  private static final int MASK_FLAGS       = 0x3FFFFFFF;

  private static final int MASK_CONSTANT      = 0x00000001; // @const
  private static final int MASK_CONSTRUCTOR   = 0x00000002; // @constructor
  private static final int MASK_DEFINE        = 0x00000004; // @define
  private static final int MASK_HIDDEN        = 0x00000008; // @hidden
  private static final int MASK_PRESERVETRY   = 0x00000010; // @preserveTry
  private static final int MASK_NOCHECK       = 0x00000020; // @notypecheck
  private static final int MASK_OVERRIDE      = 0x00000040; // @override
  private static final int MASK_NOALIAS       = 0x00000080; // @noalias
  private static final int MASK_DEPRECATED    = 0x00000100; // @deprecated
  private static final int MASK_INTERFACE     = 0x00000200; // @interface
  private static final int MASK_EXPORT        = 0x00000400; // @export
  private static final int MASK_NOSHADOW      = 0x00000800; // @noshadow
  private static final int MASK_FILEOVERVIEW  = 0x00001000; // @fileoverview
  private static final int MASK_IMPLICITCAST  = 0x00002000; // @implicitCast
  private static final int MASK_NOSIDEEFFECTS = 0x00004000; // @nosideeffects
  private static final int MASK_EXTERNS       = 0x00008000; // @externs
  private static final int MASK_JAVADISPATCH  = 0x00010000; // @javadispath
  private static final int MASK_NOCOMPILE     = 0x00020000; // @nocompile

  // 3 bit type field stored in the top 3 bits of the most significant
  // nibble.
  private static final int MASK_TYPEFIELD    = 0xE0000000; // 1110...
  private static final int TYPEFIELD_TYPE    = 0x20000000; // 0010...
  private static final int TYPEFIELD_RETURN  = 0x40000000; // 0100...
  private static final int TYPEFIELD_ENUM    = 0x60000000; // 0110...
  private static final int TYPEFIELD_TYPEDEF = 0x80000000; // 1000...

  /**
   * Creates a {@link JSDocInfo} object. This object should be created using
   * a {@link JSDocInfoBuilder}.
   */
  JSDocInfo(boolean includeDocumentation) {
    this.includeDocumentation = includeDocumentation;
  }

  // Visible for testing.
  public JSDocInfo() {}

  void setConstant(boolean value) {
    setFlag(value, MASK_CONSTANT);
  }

  void setConstructor(boolean value) {
    setFlag(value, MASK_CONSTRUCTOR);
  }

  void setDefine(boolean value) {
    setFlag(value, MASK_DEFINE);
  }

  void setHidden(boolean value) {
    setFlag(value, MASK_HIDDEN);
  }

  void setNoCheck(boolean value) {
    setFlag(value, MASK_NOCHECK);
  }

  void setShouldPreserveTry(boolean value) {
    setFlag(value, MASK_PRESERVETRY);
  }

  void setOverride(boolean value) {
    setFlag(value, MASK_OVERRIDE);
  }

  void setNoAlias(boolean value) {
    setFlag(value, MASK_NOALIAS);
  }

  // Visible for testing.
  public void setDeprecated(boolean value) {
    setFlag(value, MASK_DEPRECATED);
  }

  void setInterface(boolean value) {
    setFlag(value, MASK_INTERFACE);
  }

  void setExport(boolean value) {
    setFlag(value, MASK_EXPORT);
  }

  void setNoShadow(boolean value) {
    setFlag(value, MASK_NOSHADOW);
  }

  void setImplicitCast(boolean value) {
    setFlag(value, MASK_IMPLICITCAST);
  }

  void setNoSideEffects(boolean value) {
    setFlag(value, MASK_NOSIDEEFFECTS);
  }

  void setExterns(boolean value) {
    setFlag(value, MASK_EXTERNS);
  }

  void setJavaDispatch(boolean value) {
    setFlag(value, MASK_JAVADISPATCH);
  }

  void setNoCompile(boolean value) {
    setFlag(value, MASK_NOCOMPILE);
  }

  private void setFlag(boolean value, int mask) {
    if (value) {
      bitset |= mask;
    } else {
      bitset &= ~mask;
    }
  }

  /**
   * Returns whether the {@code @const} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isConstant() {
    return getFlag(MASK_CONSTANT) || isDefine();
  }

  /**
   * Returns whether the {@code @constructor} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isConstructor() {
    return getFlag(MASK_CONSTRUCTOR);
  }

  /**
   * Returns whether the {@code @define} annotation is present on this
   * {@link JSDocInfo}. If this annotation is present, then the
   * {@link #getType()} method will retrieve the define type.
   */
  public boolean isDefine() {
    return getFlag(MASK_DEFINE);
  }

  /**
   * Returns whether the {@code @hidden} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isHidden() {
    return getFlag(MASK_HIDDEN);
  }

  /**
   * Returns whether the {@code @nocheck} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isNoTypeCheck() {
    return getFlag(MASK_NOCHECK);
  }

  /**
   * Returns whether the {@code @preserveTry} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean shouldPreserveTry() {
    return getFlag(MASK_PRESERVETRY);
  }

  /**
   * Returns whether the {@code @override} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isOverride() {
    return getFlag(MASK_OVERRIDE);
  }

  /**
   * Returns whether the {@code @noalias} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isNoAlias() {
    return getFlag(MASK_NOALIAS);
  }

  /**
   * Returns whether the {@code @deprecated} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isDeprecated() {
    return getFlag(MASK_DEPRECATED);
  }

  /**
   * Returns whether the {@code @interface} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isInterface() {
    return getFlag(MASK_INTERFACE);
  }

  /**
   * Returns whether the {@code @export} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isExport() {
    return getFlag(MASK_EXPORT);
  }

  /**
   * Returns whether the {@code @noshadow} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isNoShadow() {
    return getFlag(MASK_NOSHADOW);
  }

  /**
   * Returns whether the {@code @implicitCast} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isImplicitCast() {
    return getFlag(MASK_IMPLICITCAST);
  }

  /**
   * Returns whether the {@code @nosideeffects} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isNoSideEffects() {
    return getFlag(MASK_NOSIDEEFFECTS);
  }

  /**
   * Returns whether the {@code @externs} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isExterns() {
    return getFlag(MASK_EXTERNS);
  }

  /**
   * Returns whether the {@code @javadispath} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isJavaDispatch() {
    return getFlag(MASK_JAVADISPATCH);
  }

  /**
   * Returns whether the {@code @nocompile} annotation is present on this
   * {@link JSDocInfo}.
   */
  public boolean isNoCompile() {
    return getFlag(MASK_NOCOMPILE);
  }

  /**
   * @return Whether there is declaration present on this {@link JSDocInfo}.
   */
  public boolean containsDeclaration() {
    return (hasType()
        || hasReturnType()
        || hasEnumParameterType()
        || hasTypedefType()
        || hasThisType()
        || getParameterCount() > 0
        || getFlag(MASK_CONSTANT
            | MASK_CONSTRUCTOR
            | MASK_DEFINE
            | MASK_OVERRIDE
            | MASK_NOALIAS
            | MASK_DEPRECATED
            | MASK_INTERFACE
            | MASK_NOSHADOW
            | MASK_IMPLICITCAST
            | MASK_NOSIDEEFFECTS));
  }

  private boolean getFlag(int mask) {
    return (bitset & mask) != 0x00;
  }

  // Visible for testing.
  public void setVisibility(Visibility visibility) {
    this.visibility = visibility;
  }

  private void lazyInitInfo() {
    if (info == null) {
      info = new LazilyInitializedInfo();
    }
  }

  /**
   * Lazily initializes the documentation information object, but only
   * if the JSDocInfo was told to keep such information around.
   */
  private boolean lazyInitDocumentation() {
    if (!includeDocumentation) {
      return false;
    }

    if (documentation == null) {
      documentation = new LazilyInitializedDocumentation();
    }

    return true;
  }

  /**
   * Adds a marker to the documentation (if it exists) and
   * returns the marker. Returns null otherwise.
   */
  Marker addMarker() {
    if (!lazyInitDocumentation()) {
      return null;
    }

    if (documentation.markers == null) {
      documentation.markers = Lists.newArrayList();
    }

    Marker marker = new Marker();
    documentation.markers.add(marker);
    return marker;
  }

  /**
   * Sets the deprecation reason.
   *
   * @param reason The deprecation reason
   */
  boolean setDeprecationReason(String reason) {
    lazyInitInfo();

    if (info.deprecated != null) {
      return false;
    }

    info.deprecated = reason;
    return true;
  }

  /**
   * Add a suppressed warning.
   */
  void addSuppression(String suppression) {
    lazyInitInfo();

    if (info.suppressions == null) {
      info.suppressions = Sets.newHashSet();
    }
    info.suppressions.add(suppression);
  }

  /**
   * Sets suppressed warnings.
   * @param suppressions A list of suppressed warning types.
   */
  boolean setSuppressions(Set<String> suppressions) {
    lazyInitInfo();

    if (info.suppressions != null) {
      return false;
    }

    info.suppressions = suppressions;
    return true;
  }

  /**
   * Add modifies values.
   */
  void addModifies(String modifies) {
    lazyInitInfo();

    if (info.modifies == null) {
      info.modifies = Sets.newHashSet();
    }
    info.modifies.add(modifies);
  }

  /**
   * Sets modifies values.
   * @param modifies A list of modifies types.
   */
  boolean setModifies(Set<String> modifies) {
    lazyInitInfo();

    if (info.modifies != null) {
      return false;
    }

    info.modifies = modifies;
    return true;
  }

  /**
   * Documents the version.
   */
  boolean documentVersion(String version) {
    if (!lazyInitDocumentation()) {
      return true;
    }

    if (documentation.version != null) {
      return false;
    }

    documentation.version = version;
    return true;
  }

  /**
   * Documents a reference (i.e. adds a "see" reference to the list).
   */
  boolean documentReference(String reference) {
    if (!lazyInitDocumentation()) {
      return true;
    }

    if (documentation.sees == null) {
      documentation.sees = Lists.newArrayList();
    }

    documentation.sees.add(reference);
    return true;
  }

  /**
   * Documents the author (i.e. adds it to the author list).
   */
  boolean documentAuthor(String author) {
    if (!lazyInitDocumentation()) {
      return true;
    }

    if (documentation.authors == null) {
      documentation.authors = Lists.newArrayList();
    }

    documentation.authors.add(author);
    return true;
  }

  /**
   * Documents the throws (i.e. adds it to the throws list).
   */
  boolean documentThrows(JSTypeExpression type, String throwsDescription) {
    if (!lazyInitDocumentation()) {
      return true;
    }

    if (documentation.throwsDescriptions == null) {
      documentation.throwsDescriptions =
          new LinkedHashMap<JSTypeExpression, String>();
    }

    if (!documentation.throwsDescriptions.containsKey(type)) {
      documentation.throwsDescriptions.put(type, throwsDescription);
      return true;
    }

    return false;
  }


  /**
   * Documents a parameter. Parameters are described using the {@code @param}
   * annotation.
   *
   * @param parameter the parameter's name
   * @param description the parameter's description
   */
  boolean documentParam(String parameter, String description) {
    if (!lazyInitDocumentation()) {
      return true;
    }

    if (documentation.parameters == null) {
      documentation.parameters = new LinkedHashMap<String, String>();
    }

    if (!documentation.parameters.containsKey(parameter)) {
      documentation.parameters.put(parameter, description);
      return true;
    } else {
      return false;
    }
  }

  /**
   * Documents the block-level comment/description.
   *
   * @param description the description
   */
  boolean documentBlock(String description) {
    if (!lazyInitDocumentation()) {
      return true;
    }

    if (documentation.blockDescription != null) {
      return false;
    }

    documentation.blockDescription = description;
    return true;
  }

  /**
   * Documents the fileoverview comment/description.
   *
   * @param description the description
   */
  boolean documentFileOverview(String description) {
    setFlag(true, MASK_FILEOVERVIEW);
    if (!lazyInitDocumentation()) {
      return true;
    }

    if (documentation.fileOverview != null) {
      return false;
    }

    documentation.fileOverview = description;
    return true;
  }

  /**
   * Documents the return value. Return value is described using the
   * {@code @return} annotation.
   *
   * @param description the return value's description
   */
  boolean documentReturn(String description) {
    if (!lazyInitDocumentation()) {
      return true;
    }

    if (documentation.returnDescription != null) {
      return false;
    }

    documentation.returnDescription = description;
    return true;
  }

  /**
   * Declares a parameter. Parameters are described using the {@code @param}
   * annotation.
   *
   * @param jsType the parameter's type, it may be {@code null} when the
   *     {@code @param} annotation did not specify a type.
   * @param parameter the parameter's name
   */
  boolean declareParam(JSTypeExpression jsType, String parameter) {
    lazyInitInfo();
    if (info.parameters == null) {
      info.parameters = new LinkedHashMap<String, JSTypeExpression>();
    }
    if (!info.parameters.containsKey(parameter)) {
      info.parameters.put(parameter, jsType);
      return true;
    } else {
      return false;
    }
  }

  /**
   * Declares a template type name. Template type names are described using the
   * {@code @template} annotation.
   *
   * @param templateTypeName the template type name.
   */
  boolean declareTemplateTypeName(String templateTypeName) {
    lazyInitInfo();

    if (info.templateTypeName != null) {
      return false;
    }

    info.templateTypeName = templateTypeName;
    return true;
  }

  /**
   * Declares that the method throws a given type.
   *
   * @param jsType The type that can be thrown by the method.
   */
  boolean declareThrows(JSTypeExpression jsType) {
    lazyInitInfo();

    if (info.thrownTypes == null) {
      info.thrownTypes = Lists.newArrayList();
    }

    info.thrownTypes.add(jsType);
    return true;
  }

  /**
   * Gets the visibility specified by {@code @private}, {@code @protected} or
   * {@code @public} annotation. If no visibility is specified, visibility
   * is inherited from the base class.
   */
  public Visibility getVisibility() {
    return visibility;
  }

  /**
   * Gets the parameter type.
   * @param parameter the parameter's name
   * @return the parameter's type or {@code null} if this parameter is not
   *     defined or has a {@code null} type
   */
  public JSTypeExpression getParameterType(String parameter) {
    if (info == null || info.parameters == null) {
      return null;
    }
    return info.parameters.get(parameter);
  }

  /**
   * Returns whether the parameter is defined.
   */
  public boolean hasParameter(String parameter) {
    if (info == null || info.parameters == null) {
      return false;
    }
    return info.parameters.containsKey(parameter);
  }

  /**
   * Returns whether the parameter has an attached type.
   *
   * @return {@code true} if the parameter has an attached type, {@code false}
   *     if the parameter has no attached type or does not exist.
   */
  public boolean hasParameterType(String parameter) {
    return getParameterType(parameter) != null;
  }

  /**
   * Returns the set of names of the defined parameters. The iteration order
   * of the returned set is not the order in which parameters are defined.
   *
   * @return the set of names of the defined parameters. The returned set is
   *     immutable.
   */
  public Set<String> getParameterNames() {
    if (info == null || info.parameters == null) {
      return ImmutableSet.of();
    }
    return ImmutableSet.copyOf(info.parameters.keySet());
  }

  /**
   * Gets the number of parameters defined.
   */
  public int getParameterCount() {
    if (info == null || info.parameters == null) {
      return 0;
    }
    return info.parameters.size();
  }

  void setType(JSTypeExpression type) {
    setType(type, TYPEFIELD_TYPE);
  }

  void setReturnType(JSTypeExpression type) {
    setType(type, TYPEFIELD_RETURN);
  }

  void setEnumParameterType(JSTypeExpression type) {
    setType(type, TYPEFIELD_ENUM);
  }

  void setTypedefType(JSTypeExpression type) {
    setType(type, TYPEFIELD_TYPEDEF);
  }

  private void setType(JSTypeExpression type, int mask) {
    if ((bitset & MASK_TYPEFIELD) != 0) {
      throw new IllegalStateException(
          "API tried to add two incompatible type tags. " +
          "This should have been blocked and emitted a warning.");
    }
    this.bitset = (bitset & MASK_FLAGS) | mask;
    this.type = type;
  }

  /**
   * Returns the list of thrown types.
   */
  public List<JSTypeExpression> getThrownTypes() {
    if (info == null || info.thrownTypes == null) {
      return ImmutableList.of();
    }
    return Collections.unmodifiableList(info.thrownTypes);
  }

  /**
   * Returns whether a type, specified using the {@code @type} annotation, is
   * present on this JSDoc.
   */
  public boolean hasType() {
    return hasType(TYPEFIELD_TYPE);
  }

  /**
   * Returns whether an enum parameter type, specified using the {@code @enum}
   * annotation, is present on this JSDoc.
   */
  public boolean hasEnumParameterType() {
    return hasType(TYPEFIELD_ENUM);
  }

  /**
   * Returns whether a typedef parameter type, specified using the
   * {@code @typedef} annotation, is present on this JSDoc.
   */
  public boolean hasTypedefType() {
    return hasType(TYPEFIELD_TYPEDEF);
  }

  /**
   * Returns whether this {@link JSDocInfo} contains a type for {@code @return}
   * annotation.
   */
  public boolean hasReturnType() {
    return hasType(TYPEFIELD_RETURN);
  }

  private boolean hasType(int mask) {
    return (bitset & MASK_TYPEFIELD) == mask;
  }

  /**
   * Gets the type specified by the {@code @type} annotation.
   */
  public JSTypeExpression getType() {
    return getType(TYPEFIELD_TYPE);
  }

  /**
   * Gets the return type specified by the {@code @return} annotation.
   */
  public JSTypeExpression getReturnType() {
    return getType(TYPEFIELD_RETURN);
  }

  /**
   * Gets the enum parameter type specified by the {@code @enum} annotation.
   */
  public JSTypeExpression getEnumParameterType() {
    return getType(TYPEFIELD_ENUM);
  }

  /**
   * Gets the typedef type specified by the {@code @type} annotation.
   */
  public JSTypeExpression getTypedefType() {
    return getType(TYPEFIELD_TYPEDEF);
  }

  private JSTypeExpression getType(int typefield) {
    if ((MASK_TYPEFIELD & bitset) == typefield) {
      return type;
    } else {
      return null;
    }
  }

  /**
   * Gets the type specified by the {@code @this} annotation.
   */
  public JSTypeExpression getThisType() {
    return thisType;
  }

  /**
   * Sets the type specified by the {@code @this} annotation.
   */
  void setThisType(JSTypeExpression type) {
    this.thisType = type;
  }

  /**
   * Returns whether this {@link JSDocInfo} contains a type for {@code @this}
   * annotation.
   */
  public boolean hasThisType() {
    return thisType != null;
  }

  void setBaseType(JSTypeExpression type) {
    lazyInitInfo();
    info.baseType = type;
  }

  /**
   * Gets the base type specified by the {@code @extends} annotation.
   */
  public JSTypeExpression getBaseType() {
    return (info == null) ? null : info.baseType;
  }

  /**
   * Gets the description specified by the {@code @desc} annotation.
   */
  public String getDescription() {
    return (info == null) ? null : info.description;
  }

  void setDescription(String desc) {
    lazyInitInfo();
    info.description = desc;
  }

  /**
   * Gets the meaning specified by the {@code @meaning} annotation.
   *
   * In localization systems, two messages with the same content but
   * different "meanings" may be translated differently. By default, we
   * use the name of the variable that the message is initialized to as
   * the "meaning" of the message.
   *
   * But some code generators (like Closure Templates) inject their own
   * meaning with the jsdoc {@code @meaning} annotation.
   */
  public String getMeaning() {
    return (info == null) ? null : info.meaning;
  }

  void setMeaning(String meaning) {
    lazyInitInfo();
    info.meaning = meaning;
  }

  /**
   * Gets the name we're lending to in a {@code @lends} annotation.
   *
   * In many reflection APIs, you pass an anonymous object to a function,
   * and that function mixes the anonymous object into another object.
   * The {@code @lends} annotation allows the type system to track
   * those property assignments.
   */
  public String getLendsName() {
    return (info == null) ? null : info.lendsName;
  }

  void setLendsName(String name) {
    lazyInitInfo();
    info.lendsName = name;
  }

  /**
   * Gets the description specified by the {@code @license} annotation.
   */
  public String getLicense() {
    return (info == null) ? null : info.license;
  }

  /** License directives can appear in multiple comments, and always
   * apply to the entire file.  Break protection and allow outsiders to
   * update the license string so that we can attach the license text even
   * when the JSDocInfo has been created and tagged with other information.
   * @param license String containing new license text.
   */

  public void setLicense(String license) {
    lazyInitInfo();
    info.license = license;
  }

  @Override
  public String toString() {
    return "JSDocInfo";
  }

  /**
   * Returns whether this {@link JSDocInfo} contains a type for {@code @extends}
   * annotation.
   */
  public boolean hasBaseType() {
    return getBaseType() != null;
  }

  /**
   * Adds an implemented interface. Returns whether the interface was added. If
   * the interface was already present in the list, it won't get added again.
   */
  boolean addImplementedInterface(JSTypeExpression interfaceName) {
    lazyInitInfo();
    if (info.implementedInterfaces == null) {
      info.implementedInterfaces = Lists.newArrayListWithCapacity(2);
    }
    if (info.implementedInterfaces.contains(interfaceName)) {
      return false;
    }
    info.implementedInterfaces.add(interfaceName);
    return true;
  }

  /**
   * Returns the types specified by the {@code @implements} annotation.
   *
   * @return An immutable list of JSTypeExpression objects that can
   *    be resolved to types.
   */
  public List<JSTypeExpression> getImplementedInterfaces() {
    if (info == null || info.implementedInterfaces == null) {
      return ImmutableList.of();
    }
    return Collections.unmodifiableList(info.implementedInterfaces);
  }

  /**
   * Gets the number of interfaces specified by the {@code @implements}
   * annotation.
   */
  public int getImplementedInterfaceCount() {
    if (info == null || info.implementedInterfaces == null) {
      return 0;
    }
    return info.implementedInterfaces.size();
  }

  /**
   * Returns the deprecation reason or null if none specified.
   */
  public String getDeprecationReason() {
    return info == null ? null : info.deprecated;
  }

  /**
   * Returns the set of suppressed warnings.
   */
  public Set<String> getSuppressions() {
    Set<String> suppressions = info == null ? null : info.suppressions;
    return suppressions == null ? Collections.<String>emptySet() : suppressions;
  }

  /**
   * Returns the set of sideeffect notations.
   */
  public Set<String> getModifies() {
    Set<String> modifies = info == null ? null : info.modifies;
    return modifies == null ? Collections.<String>emptySet() : modifies;
  }

  /**
   * Returns whether a description exists for the parameter with the specified
   * name.
   */
  public boolean hasDescriptionForParameter(String name) {
    if (documentation == null || documentation.parameters == null) {
      return false;
    }

    return documentation.parameters.containsKey(name);
  }

  /**
   * Returns the description for the parameter with the given name, if its
   * exists.
   */
  public String getDescriptionForParameter(String name) {
    if (documentation == null || documentation.parameters == null) {
      return null;
    }

    return documentation.parameters.get(name);
  }

  /**
   * Returns the list of authors or null if none.
   */
  public Collection<String> getAuthors() {
    return documentation == null ? null : documentation.authors;
  }

  /**
   * Returns the list of references or null if none.
   */
  public Collection<String> getReferences() {
    return documentation == null ? null : documentation.sees;
  }

  /**
   * Returns the version or null if none.
   */
  public String getVersion() {
    return documentation == null ? null : documentation.version;
  }

  /**
   * Returns the description of the returned object or null if none specified.
   */
  public String getReturnDescription() {
    return documentation == null ? null : documentation.returnDescription;
  }

  /**
   * Returns the block-level description or null if none specified.
   */
  public String getBlockDescription() {
    return documentation == null ? null : documentation.blockDescription;
  }

  /**
   * Returns whether this has a fileoverview flag.
   */
  public boolean hasFileOverview() {
    return getFlag(MASK_FILEOVERVIEW);
  }

  /**
   * Returns the file overview or null if none specified.
   */
  public String getFileOverview() {
    return documentation == null ? null : documentation.fileOverview;
  }

  /** Gets the name of the source file that contains this JSDoc. */
  public String getSourceName() {
    return sourceName;
  }

  /** Gets the list of all markers for the documentation in this JSDoc. */
  public Collection<Marker> getMarkers() {
    return documentation == null ? null : documentation.markers;
  }

  /** Sets the name of the source file that contains this JSDoc. */
  void setSourceName(String sourceName) {
    this.sourceName = sourceName;
  }

  /** Gets the template type name. */
  public String getTemplateTypeName() {
    if (info == null) {
      return null;
    }
    return info.templateTypeName;
  }

  /**
   * Returns a collection of all type nodes that are a part of this JSDocInfo.
   * This includes @type, @this, @extends, @implements, @param, @throws,
   * and @return.  Any future type specific JSDoc should make sure to add the
   * appropriate nodes here.
   * @return collection of all type nodes
   */
  public Collection<Node> getTypeNodes() {
    List<Node> nodes = Lists.newArrayList();

    if (type != null) {
      nodes.add(type.getRoot());
    }

    if (thisType != null) {
      nodes.add(thisType.getRoot());
    }

    if (info != null) {
      if (info.baseType != null) {
        nodes.add(info.baseType.getRoot());
      }

      if (info.implementedInterfaces != null) {
        for (JSTypeExpression interfaceType : info.implementedInterfaces) {
          nodes.add(interfaceType.getRoot());
        }
      }

      if (info.parameters != null) {
        for (JSTypeExpression parameterType : info.parameters.values()) {
          if (parameterType != null) {
            nodes.add(parameterType.getRoot());
          }
        }
      }

      if (info.thrownTypes != null) {
        for (JSTypeExpression thrownType : info.thrownTypes) {
          if (thrownType != null) {
            nodes.add(thrownType.getRoot());
          }
        }
      }
    }

    return nodes;
  }

  public boolean hasModifies() {
    return info != null && info.modifies != null;
  }

  /**
   * Returns the original JSDoc comment string. Returns null unless
   * parseJsDocDocumentation is enabled via the ParserConfig.
   */
  public String getOriginalCommentString() {
    return documentation == null ? null : documentation.sourceComment;
  }

  void setOriginalCommentString(String sourceComment) {
    if (!lazyInitDocumentation()) {
      return;
    }
    documentation.sourceComment = sourceComment;
  }
}
